Chen Kunmei, Guo Bing, Yu Chunming, Chen Ping, Chen Jikang, Gao Gang, Wang Xiaofei, Zhu Aiguo
Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, No. 348, West Xianjiahu Road, Changsha 410205, China.
Plants (Basel). 2021 Jan 15;10(1):160. doi: 10.3390/plants10010160.
The occurrence of adventitious roots is necessary for the survival of cuttings. In this study, comparative transcriptome analysis between two ramie ( L.) varieties with different adventitious root (AR) patterns was performed by mRNA-Seq before rooting (control, CK) and 10 days water-induced adventitious rooting (treatment, T) to reveal the regulatory mechanism of rooting. Characterization of the two ramie cultivars, Zhongzhu No 2 (Z2) and Huazhu No 4 (H4), indicated that Z2 had a high adventitious rooting rate but H4 had a low rooting rate. Twelve cDNA libraries of the two varieties were constructed, and a total of 26,723 genes were expressed. In the non-water culture condition, the number of the distinctive genes in H4 was 2.7 times of that in Z2, while in the water culture condition, the number of the distinctive genes in Z2 was nearly 2 times of that in H4. A total of 4411 and 5195 differentially expressed genes (DEGs) were identified in the comparison of H4CK vs. H4T and Z2CK vs. Z2T, respectively. After the water culture, more DEGs were upregulated in Z2, but more DEGs were downregulated in H4. Gene ontology (GO) functional analysis of the DEGs indicated that the polysaccharide metabolic process, carbohydrate metabolic process, cellular carbohydrate metabolic process, cell wall macromolecule metabolic process, and photosystem GO terms were distinctively significantly enriched in H4. Simultaneously, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that photosynthesis, photosynthesis antenna proteins, and starch and sucrose metabolism pathways were distinctively significantly enriched in H4. Moreover, KEGG analysis showed that jasmonic acid (JA) could interact with ethylene to regulate the occurrence and number of AR in Z2. This study reveals the transcriptomic divergence of two ramie varieties with high and low adventitious rooting rates, and provides insights into the molecular regulatory mechanism of AR formation in ramie.
不定根的发生是插条存活所必需的。在本研究中，通过mRNA测序对两个具有不同不定根（AR）模式的苎麻品种在生根前（对照，CK）和水培诱导不定根10天（处理，T）进行比较转录组分析，以揭示生根的调控机制。对两个苎麻品种中苎2号（Z2）和华苎4号（H4）的特性分析表明，Z2的不定根生根率高，而H4的生根率低。构建了两个品种的12个cDNA文库，共表达了26723个基因。在非水培条件下，H4中特异基因的数量是Z2中的2.7倍，而在水培条件下，Z2中特异基因的数量几乎是H4中的2倍。在H4CK与H4T以及Z2CK与Z2T的比较中，分别鉴定出4411个和5195个差异表达基因（DEG）。水培后，Z2中有更多的DEG上调，但H4中有更多的DEG下调。对DEG的基因本体（GO）功能分析表明，多糖代谢过程、碳水化合物代谢过程、细胞碳水化合物代谢过程、细胞壁大分子代谢过程和光系统GO术语在H4中显著富集。同时，京都基因与基因组百科全书（KEGG）分析表明，光合作用、光合作用天线蛋白以及淀粉和蔗糖代谢途径在H4中显著富集。此外，KEGG分析表明，茉莉酸（JA）可以与乙烯相互作用来调节Z2中AR的发生和数量。本研究揭示了两个不定根生根率高低不同的苎麻品种的转录组差异，并为苎麻AR形成的分子调控机制提供了见解。
